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Fulltext Immunogenicity and protective efficacy of a live, oral cholera vaccine formulation stored outside-the-cold-chain for 140 days

Xian TH, Sinniah K, Yean CY, Krishnamoorthy V, Bahari MB, Ravichandran M, et al.

BMC Immunol, 2020 05 25;21(1):29.
PMID: 32450807 DOI: 10.1186/s12865-020-00360-1

BACKGROUND: Cholera, an acute watery diarrhoeal disease caused by Vibrio cholerae serogroup O1 and O139 across the continents. Replacing the existing WHO licensed killed multiple-dose oral cholera vaccines that demand 'cold chain supply' at 2-8 °C with a live, single-dose and cold chain-free vaccine would relieve the significant bottlenecks and cost determinants in cholera vaccination campaigns. In this direction, a prototype cold chain-free live attenuated cholera vaccine formulation (LACV) was developed against the toxigenic wild-type (WT) V. cholerae O139 serogroup. LACV was found stable and retained its viability (5 × 106 CFU/mL), purity and potency at room temperature (25 °C ± 2 °C, and 60% ± 5% relative humidity) for 140 days in contrast to all the existing WHO licensed cold-chain supply (2-8 °C) dependent killed oral cholera vaccines.
RESULTS: The LACV was evaluated for its colonization potential, reactogenicity, immunogenicity and protective efficacy in animal models after its storage at room temperature for 140 days. In suckling mice colonization assay, the LACV recorded the highest recovery of (7.2 × 107 CFU/mL) compared to those of unformulated VCUSM14P (5.6 × 107 CFU/mL) and the WT O139 strain (3.5 × 107 CFU/mL). The LACV showed no reactogenicity even at an inoculation dose of 104-106 CFU/mL in a rabbit ileal loop model. The rabbits vaccinated with the LACV or unformulated VCUSM14P survived a challenge with WT O139 and showed no signs of diarrhoea or death in the reversible intestinal tie adult rabbit diarrhoea (RITARD) model. Vaccinated rabbits recorded a 275-fold increase in anti-CT IgG and a 15-fold increase in anti-CT IgA antibodies compared to those of rabbits vaccinated with unformulated VCUSM14P. Vibriocidal antibodies were increased by 31-fold with the LACV and 14-fold with unformulated VCUSM14P.
CONCLUSION: The vaccine formulation mimics a natural infection, is non-reactogenic and highly immunogenic in vivo and protects animals from lethal wild-type V. cholerae O139 challenge. The single dose LACV formulation was found to be stable at room temperature (25 ± 2 °C) for 140 days and it would result in significant cost savings during mass cholera vaccination campaigns.

Matched MeSH terms: Antibody Formation/immunology*
Fulltext Hemolytic disease of the fetus and newborn caused by anti-E

Usman AS, Mustaffa R, Ramli N, Diggi SA

Asian J Transfus Sci, 2013 Jan;7(1):84-5.
PMID: 23559775 DOI: 10.4103/0973-6247.106750

OBJECTIVE: Maternal allo-antibody production is stimulated when fetal red blood cells are positive for an antigen absent on the mother's red cells. The maternal IgG antibodies produced will pass through the placenta and attack fetal red cells carrying the corresponding antigen. Allo-immune hemolytic disease of the fetus and newborn caused by anti-E rarely occurs.
CASE SUMMARY: We report two cases of anti-E hemolytic diseases in neonates. One of the neonates had severe hemolysis presenting with severe anemia, thrombocytopenia, and conjugated hyperbilirubinemia, while the other had moderate anemia and unconjugated hyperbilrubinemia. Although both the neonates were treated by phototherapy and intravenous immunoglobulin, one of them received double volume exchange transfusion.
CONCLUSION: There appeared to be an increase in the occurrence of hemolytic disease of the fetus and newborn caused by Rh antibodies other than anti-D. In this case report, both patients presented with anemia and hyperbilirubinemia but were successfully treated, with a favorable outcome.

Matched MeSH terms: Antibody Formation
Immunogenicity of a truncated enterovirus 71 VP1 protein fused to a Newcastle disease virus nucleocapsid protein fragment in mice

Ch'ng WC, Saw WT, Yusoff K, Shafee N

Acta Virol., 2011;55(3):227-33.
PMID: 21978156

Enterovirus 71 (EV71) is one of the viruses that cause hand, foot and mouth disease. Its viral capsid protein 1 (VP1), which contains many neutralization epitopes, is an ideal target for vaccine development. Recently, we reported the induction of a strong immune response in rabbits to a truncated VP1 fragment (Nt-VP1t) displayed on a recombinant Newcastle disease virus (NDV) capsid protein. Protective efficacy of this vaccine, however, can only be tested in mice, since all EV71 animal models thus far were developed in mouse systems. In this study, we evaluated the type of immune responses against the protein developed by adult BALB/c mice. Nt-VP1t protein induced high levels of VP1 IgG antibody production in mice. Purified VP1 antigen stimulated activation, proliferation and differentiation of splenocytes harvested from these mice. They also produced significant levels of IFN-γ, a Th1-related cytokine. Taken together, Nt-VP1t protein is a potent immunogen in adult mice and our findings provide the data needed for testing of its protective efficacy in mouse models of EV71 infections.

Matched MeSH terms: Antibody Formation

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